System and method for balloon yarding and otherwise transporting objects between two locations

ABSTRACT

A system for balloon yarding employs a lighter-than-air balloon to suspend a carriage. A choker cable for grasping logs is attached to the carriage. An idler sheave is rotatably mounted on the carriage. Inhaul and outhaul sheaves are secured to the ground at spaced locations. A set of drive sheaves and a drum are mounted for rotation at a location near the inhaul sheave. One end of a continuous cable is attached to the carriage and runs through the outhaul block, engages the drive sheaves, and runs through the inhaul block and the idler sheave and back to the drum about which it is wrapped. A clamp, removably fixed to the cable between the idler sheave on the carriage and the drum, abuts against the carriage to limit the amount of line which can be payed out from the drum through the idler sheave. In this manner the effective length of the main portion of the cable, running from the carriage through the inhaul, outhaul and drive sheaves, and back to the idler sheave, is limited to a predetermined length. A drive mechanism is also provided for independently, selectively, and reversibly rotating and for independently and selectively braking both the take-up drum and the drive sheaves.

United States Patent [191 Langford SYSTEM AND METHOD FOR BALLOON YARDING AND OTHERWISE TRANSPORTING OBJECTS BETWEEN TWO LOCATIONS [75] Inventor: Frederic E. Langford, Redmond,

Wash.

[73] Assignee: Formac International Inc., Seattle,

Wash.

[22] Filed: Feb. 22, 1974 [21] Appl. No.: 444,909

[52] U.S. Cl..... 212/71, 244/33 [51] Int. Cl. B66c 21/00 0 Field or Search 244/33; 212/71, 76, 97,

[111 3,865,251 [451 Feb. 11, 1975 Primary Examiner-Trygve M. Bix Assistant Examiner-Galen L. Barefoot [57] ABSTRACT A system for balloon yarding employs a lighter-thanair balloon to suspend a carriage. A choker cable for grasping logs is attached to the carriage. An idler sheave is rotatably mounted on the carriage. lnhaul and outhaul sheaves are secured to the ground at spaced locations. A set of drive sheaves and a drum are mounted for rotation at a location near the inhaul sheave. One end of a continuous cable is attached to the carriage and runs through the outhaul block, engages the drive sheaves, and runs through the inhaul block and the idler sheave and back to the drum about which it iswrapped. A clamp, removably fixed to the cable between the idler sheave on the carriage and the drum, abuts against the carriage to limit the amount of line which 'can be payed out from the drum through the idler sheave. In this manner the effective length of the main portion of the cable, running from the carriage through the inhaul, outhaul and drive sheaves, and back to the idler sheave, is limited to a predetermined length. A drive mechanism is also provided for independently, selectively, and reversibly rotating and for independently and selectively braking both the take-up drum and the drive sheaves.

11 Claims, 6 Drawing Figures may PATENTEDFEBI 1 I975 SHEET 2 BF 3 PATENTED FEB l 1 I975 sum 30F 3 raw- SYSTEM AND METHOD FOR BALLOON YARDING AND OTHERWISE TRANSPORTING OBJECTS BETWEEN TWO LOCATIONS BACKGROUND OF THE INVENTION The invention relates to a system and to methods for transporting objects from one location to another, and more particularly to a system and methods for yarding logs using a lighter-than-air balloon to suspend the logs.

Prior balloon yarding systems have employed a balloon from which a carriage is suspended. The carriage carries apparatus for grasping a log or turn of logs, the weight of which is less than the net lift of the balloon. Two cables are attached to the carriage. One cable (the outhaul cable) is run through the outhaul block and back to a drum at a staging area. The other cable (the inhaul cable) is run from the carriage through an inhaul sheave to a second drum at the staging area. The balloon and carriage are lowered, raised and transported between the inhaul and outhaul sheaves by differentially and selectively driving the two drums.

The two cables must be sufficiently strong to withstand the line tension created by both the balloon lift and the driving forces generated as the balloon is being accelerated and moved between the inhaul and outhaul sheaves. As the balloons become larger, generating lift on the order of fifty thousand pounds, the line tensions become rather large as the balloon is moved between the inhaul and outhaul sheaves, especially when the balloon is not supporting a load. The present state of technology can provide cables to withstand such line tensions. A problem arises, however, in providing a drive train, including drive shafts and gear boxes,.which can transmit the requisite horsepower between a prime mover and the drums. Presently very large, cumbersome and expensive drive trains must be employed to provide an operable system which will not disintegrate when the balloon is being moved at high speeds.

It is an ojbect of the present inventionto provide a system and methods for transporting a load, such as a log or turn of logs, between two spaced locations at high speeds using a high lift, lighter-than-air balloon to suspend the load above the ground. It is another object of the present invention to provide a yarding system which employs a continuous line or cable driven by traction (or drive) sheaves, which system isolates the sheave drive train from the tension forces in the line caused byballoon lift. Corollary objects are to provide a yarding system in which the traction sheaves replace the inhaul and outhaul drums used in prior art yarding systems; to provide a yarding system employing a drum, on which one end of the continuous line is wrapped to assist in lowering the balloon toward the ground and to control its ascent from the ground.

Other related objects are to provide means for isolating the take-up portion of the cable, running from the carriage to the drum, and thus the drum and itsdrive train from the tension, created in the main portion of the line as the balloon traverses from one location to another; to provide means for independently, selectively, and reversibly rotating the drive sheaves and the drum; to'provide means for independently and selectively braking the drive sheaves and the drum; to provide a means which cooperates with the carriage to limit the amount of line which can be payed out and taken up with the drum, and to provide a yarding system including a drum on which cable can be stored so that the effective length of the main portion of the cable can be lengthened or shortened at will.

SUMMARY OF THE INVENTION The foregoing objects, and other objects which will become apparent upon reading the following specification, are realized in a system for moving objects between two locations which includes a lighter-than-air balloon attached to and suspending a carriage. The carriage is adapted to support and carry objects and has an idler sheave mounted for rotation thereon. The system also includes at least one drive sheave, an outhaul sheave, an inhaul sheave and a drum. The inhaul sheave and the outhaul sheave'are fixed relative to the ground in a suitable manner. The first end of a continuous cable is attached to the carrier while the second end of the cable is wrapped around the drum. Upon rotation, the drum is capable of taking up and paying out cable. The cable runs from its first end through the outhaul sheave, from the outhaul sheave through the drive sheave, from the drive sheave through the inhaul sheave, from the inhaul sheave through the idler sheave on the carriage, and from the idler sheave to the drum. A stop means is fixed to the cable between the idler sheave and the drum. The stop means cooperates with the carriage by abutment thereagainst to limit the length of cable capable of being payed out from the drum through the idler sheave and to fix the effective length of the-cable running from the first end through the outhaul, drive and inhaul sheaves and back to the carriage. First means is provided for selectively and reversibly rotating the drive sheave to reversibly drive the cable thereby moving the carriage between the outhaul sheave and the inhaul sheave. Second means is provided for selectively and reversibly rotating the drum to perform the following functions: (1) to pay out cable therefrom through the idler sheave until the stop means cooperates with the carriage to limit the length of cable which is payed through the idler sheave, and to pay out additional cable therefrom to create slack in the cable between the drum and the carriage; (2) to take up cable thereon through the idler sheave to lower the carriage relative to the ground; (3) to pay out a'sufficient length of cable therefrom to maintain slack in the cable between the drum and the carriage as the first means is rotating the drive sheave to move the carriage from the inhaul sheave toward the outhaul sheave, and (4) to take up cable thereon while maintaining slack in the cable between the carriage and the drum as the first means is rotating the drive sheave to move the carriage from the outhaul sheave toward the inhaul sheave.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention will be derived from reading the ensuing specification in conjunction with the accompanying drawings wherein:

FIG. 1 is an isometric view of the entire balloon yarding system of the present invention;

FIG. 2 is an isometric view of the carriage assembly used with the balloon yarding system illustrated in FIG.

FIG. 3 is an isometric view of the motive elements and related drive mechanisms for the balloon yarding system illustrated in FIG. 1;

FIG. 4 is a simplified schematic diagram of the yarding system illustrated in FIG. 1 as it functions to allow DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1, the aerial transportation system illustrated is vused for hauling high tonnage loads over relatively short distances in otherwise inaccessible or rough terrain. This system is most commonly used for yarding logs in remote and mountainous terrain. The

balloon yarding system eliminates much of the cost and waste of logging road construction, reduces log breakage, spares young trees and ground cover from destruction and conserves soil by reducing those factors which cause erosion. The yarding system is predictated on the use of a helium-filled balloon to provide the lifting force for the load. Motive power and control of the balloon is provided by an engine powered yarder, generally designated 12. The balloon .10 and yarder 12 are interconnected by a single continuous cable via a series of blocks. The cable, generally designated 14, through manipulation of the yarder controls (not shown) and the unique manner in which the cable is deployed, performs all inhaul, outhaul, raising and lowering functions in the yarding operation. Practical hauling distances for a system of this type range from a few hundred feet to well over a mile.

Since the balloon 10 is not dependent upon aerodynamic lift to help support the load, it operates at full capacity at all times. The balloon 10 has a spherical upper section joined to a conical lower section, which provides room for gas expansion resulting from atmospheric, temperature and pressure variations. Suspension lines 18 are deployed around the full circumference of the spherical portion 22 of the balloon 10 and are joined together below the conical section 18 to form a junction 24 at which a tether line 26 is attached. The lower end of the tether line 26 is attached by a suitable swivel connector to.a carriage assembly 28.

As shown in FIG. 2 the carriage assembly includes a housing 30 in which a sheave 32 is rotatably mounted. Two cable positioning sheaves 31 and 33 are also rotatably mounted on the carriage outboard of the sheave 32. The balloon tether line 26 is attached to the upper portion of the housing 30. The outhaul portion 14a of the yarding cable 14 is fixed to the carriage and runs toward the ground, while the inhaul portion 14b approaches the assembly 28 from the ground and engages the cable positioning sheave 33 and the idler sheave 32. The take-up portion 140 of the cable runs from the idler sheave 32, through the other positioning sheave 3] and back to the yarder 12 (FIG. 1). The purpose of the positioning sheaves 31 and 33 is to locate the exit points of the cables 14b and 140 from the carriage as sembly 28 at substantially the same position so that the carriage assembly will not be rotated about a transverse axis as force is applied to one or the other of the cables 14b and 140. If the cable merely exited to the yarder 12 from the idler sheave 32, the carriage would be unnecessarily rotated about an axis running substantially 4 through the idler sheave shaft as differential tension is placed on the cables 14b and 14c. A clamp 36 is removably affixed by suitable fasteners to the take-up portion 14c of the yarding cable. Its function will be explained in greater detail below. A choker cable 38, attached to the lower end of the carriage, suspends a log 16 (FIG. I) or turn of logs for transport from an area being logged to a staging area where the logs can be picked up by trucks for removal to a sawmill. Thus, the lifting force of the balloon I0 is coupled to the log 16 via the choker cable 38, carriage assembly 28, and tether line 26.

Referring back to FIG. 1, the continuous cable I4 incorporates an outhaul portion 14a, an inhaul portion 14b and a take-up portion 14c. The outhaul portion runs from the carriage assembly 28 through an outhaul block 86, corner blocks 84 and 82 and through a set of traction sheaves 56 on the yarder 12. The inhaul portion 14b runs from the traction sheaves back to the carriage via corner block 80 where it engages the idler sheave 32. The take-up portion 140 of the cable runsv from the idler sheave, through a take-up block 74, and

back to the yarder 12 where it is wrapped on a take-up drum 58. Each of the inhaul, outhaul, corner andtakeup blocks carries'a sheave with which the cable 14 is engaged. i

The yarder 12, isolated in FIG. 3, is the power and control unit for the balloon yarding system and is typically incorporated onto a self-propelled tractor or other wheel mounted vehicle. power is provided to the yarder by a diesel engine 40,0r other-suitable prime mover. The drive train from the engine includes a variable speed torque converter 41 coupled to a multispeed reversible transmission 42 via a drive shaft 54. A chain drive mechanism 44 couples the transmission output shaft to a drive shaft 46. For clutches 48, 50, 51, and 52 on the drive shaft 46 provide selective power take-off to pinion 68, chain drives 66 and 67, and pinion 60, respectively. The reversible transmission 42, allows the drive shaft 46 to be operated in either rotational direction.

The yarder 12 controls two motive elements which interface with the continuous cable 14 of the yarding system and drive the cable through various modes of operation to complete a yarding cycle, including picking up logs at the loading area, raising the logs above the ground and transporting them to the staging area, lowering the logs to the ground, and returning the balloon and carriage to the loading area. The two motive elements comprise a plurality of traction or drive sheaves 56 and a cable take-up drum 58. The traction sheaves 56 are rotatably mounted on a carrier shaft 57. A corresponding set of idler sheaves 59 are mounted on a parallel. carrier shaft 61. The traction sheaves are selectively and reversibly rotated by the yarder drive shaft 46 through the clutch-controlled pinion 60 which engages adriven'pinion 62 coupled to the traction sheaves. The outhaul portion 14a of the cable serially engages the traction sheaves 56'and the idler sheaves 59 in a series of turns with the inhaul portion 14b of the cable returning to the carriage. Sufficient friction is developed between the traction sheaves and the cable to impart movement to the cable. A brake disc 64 is coupled to the driven pinion 62. Brake calipers 65 are provided on the yarder to selectively engage the disc so that the rotation of the traction sheaves can be slowed or stopped at will.

.The take-up end 14c of the continuous cable is wrapped on the take-up drum 58 also mounted for rotation on shaft 57. The take-up drum is so constructed as to potentially accommodate a length of cable substantially longer than the total span of the balloon traverse. The drum 58 is driven from the yarder drive shaft 46 from one of three clutch-operated power takeoffs. The first and second power take-offs are chain drives 66 and 67 which are coupled to the drum and cause the drum to rotate in the same direction as the drive shaft 46. As explained below, it is desirableto maintain slack in the take-up line 140 when the carriage is traversing between the staging area and the loading area. The two chain drives 66 and 67 are provided with a large driven sprocket 69 and a small driven sprocket 71, respectively. The different sprocket sizes vary the speed of the drum relative to the traction sheaves to compensate for the varying wrap diameter of the line 14c on the drum 58.

Thus as line is being paid out fromthe drum (i.e., when the wrap diameter is large compared to the traction sheaves 56), clutch 50 is engaged ,to drive the larger sprocket 69 causing the drum to rotate at a first speed slightly slower than the traction sheaves 56. If line is being payed out too slowly as the carriage is being moved outwardly to the loading area, clutch 50 is allowed to slip. The carriage will then be able to pull additional take-up line 140 off the drum to maintain slack in that line. Care must be taken under most operating conditions not to completely disengage the clutch as the sheer weight of the take-up line 14c itself may cause too much line to unreel from the drum. Likewise, when the'drum is taking in line (i.e., when the wrap diameter is small relative to the traction sheaves 56), clutch 50 is disengaged and clutch 51 is engaged to drive the smaller driven sprocket 71 via chain drive 67. As line is being taken up by the drum, the drum is rotated faster to compensate for the small wrap diameter on the drum 58. As the wrap diameter increases, clutch 51 can be momentarily slipped to slow down the drum in order to equalize the incoming speed of the take-up line relative to the carriage. Thus the speed of the takeup line inboth the outhaul and the inhaul modes of ope ration can be maintained such that the take-up line is operated in a slack condition to isolate it from the tension in the inhaul and outhaul lines created by the balloon lift and the drive forces in those lines.

The other power take-off for the drum is drive pinion 68 which meshes with driven pinion 70, coupled to the drum 58, which imparts rotation to the drum in a direction opposite to that of the drive shaft 46. This double drive arrangement allows the drum to be rotated in either direction regardless of the direction of rotation of the drive shaft'. Likethe traction sheaves 58, a disc and caliper brake assembly 72 is coupled to the drum to selectively slow or stop the rotation of the drum.

To operate the yarder through the take-up drum and traction sheave drive arrangements, the yarder 12 is provided with several controls. These controls include means for controlling the reversible transmission 42 to reverse the direction of rotation of drive shaft 46, an engine throttle for controlling drive shaft rotational speed, and means for selectively and independently operating the drum drive pinion clutch 48, the take-up drum chain drive clutch 50, the take-up drum brake 72, the traction sheave pinion clutch 52 and the traction sheave brake 64. The construction of these controls are well within the ordinary skill in the art and, therefore,

. are not explained in greater detail herein. The methods by which the foregoing apparatus can be operated to complete a yarding cycle also forms a part of the present invention and are described below.

Referring to FIGS. 1 and 3 through 6 the log loading area can be at or near either the inhaul block or the outhaul-block 86. However, for purposes of this description the loading area, generally designated 78, is adjacent the outhaul block 86 while the staging (or unloading) area, generally designated 88, is adjacent the inhaul block 80. The balloon traverses the span between the staging area and the loading area at a substantially constant height. At both both ends of the span, the balloon 10 must be lowered to facilitate loading and unloading and then raised for the traverse to the opposite end of the span. The operation of the functional elements of the'system, is separated into six modes: raising the balloon from the staging area; moving the balloon to the loading area; lowering the balloon to the loading area; raising the balloon from the loading area; returning the balloon to the staging area;

and lowering the balloon back to the staging area.

The frist operating mode, which encompasses raising the unloaded balloon 10 .to traverse height from the staging area adjacent to the inhaul sheave 80, is schematically illustrated in FIG. 4. The balloon, whether loaded or unloaded, constantly exerts a lifting force on the carriage 28 creating continuous tension in the cable 14. Thus, the take-up line 14c tends to be drawn from the take-up drum 58 through take-up block 74. By braking the traction sheave 56 to prevent it from rotating and by disengaging both take-up drum clutches, cable is-payed from the takeup drum 58. The take-up drum brake can be used to control the speed at which the cable leaves the drum. As the cable is payed out, it passes through the take-up block 74 and over the idler sheave 32 in the carriage 28, allowing the carriage assembly 28 and the balloon to ascend from the unloading area and at the same time increasing the effective length of the inhaul and outhaul lines 14a and 14b. Take-up line 14c is payed out until the clamp 36 (or stop means) affixed to the take-up line 14c abuts against the carriage assembly 28 to stop the ascent of the balloon at the position indicated by the dotted portion of the illustration. Additional take-up line is payed out from drum 28 to create a slack condition therein. The location at which clamp 36 is attached to the take-up line 14c governs the altitude to which the balloon l0 traverses. When the term slack or slack condition is used herein, it is meant that the cable hangs freely between the carriage assembly and the drum,

' while preferably being elevated above the ground to keep it free from obstacles between the loading area and the staging area. In this manner, as the clamp abuts the carriage and slack is payed into the cable, the line tension from driving the balloon and from the lift of the balloon itself is isolated from the take-up line 140 and concentrated in the inhaul and outhaul lines.

The second operating mode, which encompasses moving the balloon 10 at traverse altitude from the staging area 88 to the loading area 78, is illustrated in FIG. 5. The outgoing traverse or outhaul of the balloon 10 is accomplished primarily by redistributing cable within the system. The transmission 42 of the yarder is placed in a forward drive mode which rotates the traction sheaves 56 in a clockwise direction. The clutches for the take-up drum chain drive 66 and traction sheave drive pinion 60 are engaged while the respective time the traction'sheaves 56 draw outhaul line 14a through the outhaul block 86 and reapportion it through the inhaul block 80 to the inhaul portion 14b of the cable. After the balloon 10 is drawn to the loading area 78 by the outhaul line 14a, the traction sheaves are stopped to position the balloon over the loading area. During the entire outhaul of the balloon the clamp 36 abuts against the carriage assembly.

In the third operating mode the balloon is lowered to the loading area 78 as'schematically illustrated in FIG. 6. To accomplish this result, the take-up line 140 is shortened to pull the carriage assembly 28 and the bal loon 10 toward the ground. Initially, the traction sheave drive pinion clutch is engaged and the transmission 42 of the yarder 12 is placed in a forward drive mode which rotates the traction sheaves 56 in a clockwise direction. The take-up drum drive pinion clutch is also engaged, rotating the take-up drum 58 to reel in take-up line 140. As a result outhaulline 14a isdrawn through outhaul block 86 and through traction sheaves 56, and is payed through inhaul block 80. At the same time take-up drum 58 reels in the cable through the idler sheave 32 on the carriage and the take-up block 74. In this manner the effective length of the inhaul line 14b and outhaul line 14a is shortened, lowering the carriage assembly and the balloon toward the loading area 78 as indicated by the dotted portion of FIG. 6. In this position the clamp 36 no longer abuts against the carriage 28. i

The fourth operating mode, wherein the balloon 10 is allowed to ascend from the loading area 78 to traverse altitude after the log or turn of logs is attached to. the carriage, is the reverse of the third operating mode. The balloon is allowed to rise by increasing the effective length of the inhaul and outhaul lines 14b and 14a. Initially, the transmission 42 of the yarder 12 is placed in a reverse drive mode andthe traction sheave drive pinion clutch is engaged to rotate the traction sheaves 56 in a counter-clockwise direction, opposite to that shown in FIG. 6. The take-up drum drive pinion clutch is also engaged to pay out line from the take-up drum 58 through the take-up block 74 and through the idler sheave 32. The. traction sheaves simultaneously draw cable through the idler sheave and the inhaul block 80, while the lift of the balloon draws cable from the traction sheaves 56 and through the outhaul block 86, allowing the carriage and balloon to ascend with a load. This operation continues until the clamp 36 again abuts against the carriage assembly to halt the ascent, to fix the traverse altitude of the balloon, and to create a slack condition in the take-up line 140.

Thereafter the system is operated in the fifth operating mode to transport the balloon and its load at traverse altitude from the loading area to the staging area. The fifth mode is the opposite of the second operating mode illustrated in FIG. 5, with the exception that the clutch for chain drive 67 (FIG. 3) is engaged instead of the clutch for chain drive 66. As with the outgoing traverse, the incoming traverse is a matter of redistributing the cable within the system. The transmission is placed in a reverse drive mode and thetraction sheave drive pinion clutch is engagedto rotate the traction sheavesin a counterclockwise direction, opposite to that shown in FIG. 5. The clutch for take-up drum chain drive 67 is also engaged to reel in take-up line 140 on the take-up drum. The take-up drum is operated at a speed sufficient to maintain slack in the take-up line 140 between the drum and the carriage assembly. As the balloon and its load approach the staging area, the drum andtraction sheave drives are declutched and the appropriate brakes are applied to cause the ballon and its load to come to rest.

In the sixth operating mode, the loaded balloon is lowered from traverse altitude to the staging area by operating the system in a reverse manner to that schematically illustrated in FIG. 4. The balloon is lowered by first locking the traction sheave brake to prevent the traction sheaves 56 from rotating. The yarder'transmission is maintained in the reverse drive mode as in the fifth mode. The take-up drum chain drive is then clutched to rotate the take-up drum 58 in a clockwise direction to reel in line through the idler sheave. Thus the effective length of the inhaul and outhaul cables is shortened to bring the balloon and its load toward the ground where the log or turn of logs is detached from the carriage assembly.

The operation of the yarding system disclosed herein has been described in six separate steps for purposes of clarity and ease of understanding. One of ordinary skill in the art' will readily understand that the first three modes of operation can be made continuous, as can the last three modes, by appropriate manipulation of the yarder controls. That is, the balloon and carriage assembly need not be brought to a halt between the ascent, traverse and lowering modes of operation. Further, the system has been described as it is used to yard log, although it is readily apparent that the system can be used to transport objects other than logs between two or more locations. I

The yarding system has'several advantages. Among the greatest of advantages is the use of the traction sheaves and the take-up drum in conjunction with the clamp or stop means on the take-up line. Use of this arrangement allows the line tension created by balloon lift to be isolated from the drive train. Of course, the requisite power to traverse the balloon must be transmitted through the drive train, butthis power requirement is not additive with the line tension. This factor becomes most important when the unloaded carriage and balloon are being moved from the staging area to the loading area. During this traverse, line tension is the greatest since the full net lift of the balloon is being exerted on the inhaul and outhaul lines. With line speeds on the order of 2,000 feet per minute, using the present system, the drive train must be capable of transmitting on the order of 500 horsepower. However, with a prior art system employing a outhaul drum and an inhaul drum in whichthe line tension, for example from a balloon exerting fifty thousand pounds of lift, is not isolated from the drive train, the drive train must be capable of transmitting on the order of 2,500 horsepower at line speeds of 2,000 feet per minute. The manufacturing and maintenance costs of drive trains, such as a gear box, capable of handling the latter horsepower requirements are extremely high compared to drive trains capable of handling the horsepower requirements of the present invention.

The horsepower requirements to lower and raise the balloon at relatively low line speeds are substantially less than the traverse power requirements. During traverse the stop means on the take-up line cooperates with the carriage to allow a slack condition in the takeup line, isolating the take-up drum from the line tension. Thus the drive train for the take-up drum of the present system need be sized only to handle lowering and raising requirements. Further, by relocating the clamp or stop means on the take-up line and by paying out extra line fromthe take-up drum (or by storing excess line on the drum) the overall length of the inhaul and outhaul lines can be altered so that the location of the outhaul block can easily be changed to vary the yarding distance.

The drive train of the yarding system of the present invention employs a torque converter, a reversible transmission, a gear drive for the traction sheaves, and both gear and chain drives for the take-up drum, allowing the latter to be driven in a direction the same as or opposite to the traction sheaves. Other types of drive connections can be used, but those depicted are preferred. This drive arrangement enjoys great flexibility and places a lesser demand on the operator than do other drive trains which might be employed.

Although the present invention has been described in 'relation to a preferred embodiment, various alterations, substitutions of equivalents, and other changes can be made by one of ordinary skill in the art without departing from the concepts disclosed herein. It is therefore intended that the invention be limited only by the definition contained in the appended claims.

What is claimed is: 1. A system for transporting objects between two locations comprising: a prime mover; a plurality of drive sheaves and means mounting said drive sheaves for rotation; first drive means operatively associated with said prime mover for selectively and reversibly rotating said drive sheaves; a drum and means mounting said drum for rotation; second drive means operatively associated with said prime mover for selectively and reversibly rotating said drum; I a carriage means having means thereon for suspending objects therefrom, said carriage means having a lighter-than-air balloon attached thereto to suspend said carriage means and said objects in the air; said carriage means having an idler sheave mounted for rotation thereon; an outhaul sheave spaced from said drive sheaves; cable means connected to said carriage means, said cable means extending from said carriage means and engaging said outhaul sheave, said cable means extending from said outhaul sheave to an engaging said drive sheaves, said cable means extending from said drive sheaves back to said carriage means 7 and engaging said idler sheave, said cable means extending from said idler sheave to and being wrapped on said drum; and,

stop means fixed to said cable means between said drum and said carriage means, said stop means for abutting said carriage means to limit the length of cable which can be payed out from said drum to and through said idler sheave on said carriage means.

2. The system of claim 1 wherein said stop means is removably affixed to said cable so that said stop means can be' positioned at various locations along said cable to shorten and lengthen the length of cable running from said carriage means, through said outhaul sheave, said drive sheaves and said idler sheave, and back to said stop means.

3. The system of claim 1 further comprising:

first brake means operatively associated with said plurality of drive sheaves and said first drive means for preventing rotation of said drive sheaves when said second drive means is rotating said drum.

4. The system of claim 1 further comprising:

second brake means operatively associated with said drum and said second drive means for preventing rotation of said drum when said first drive means is rotating said drive sheaves.

5. In a system for moving objects between two points,

said system including acarriage having a means for holding objects attached thereto, said carriage having an idler sheave mounted for rotation thereon, said system further including at least one drive sheave, an outhaul sheave spaced from said drive sheave, a drum, and a cable having a first end and a second end, said drive sheave andsaid'outhaul sheave being stationary relative to the ground, said first end of said cable being attached to said carriage and said second end of said cable being wrapped about said drum, said drum upon rotation being capable of taking up and paying out said cable, said cable from said first end running through said outhaul sheave, from said outhaul sheave through said drive sheave, from said drive sheave through said idler sheave, and from said idler sheave to said drum, the improvement comprising: a

a lighter-than-air balloon attached to said carriage stop means fixed to said cable between said idler sheave and said drum, said stop meansfor cooperating with said carriage to limit the length of said cable capable ofbeing payed out from said drum through said idler sheave and to fix the effective length'of said cable from said first end through said outhaul sheave and said drive sheave and back to said carriage,

first means for reversibly rotating said drive sheave to drive said cable and thereby move said carriage between said outhaul sheave and said drive sheave,

second means for selectively and reversibly rotating said drum 1. to pay out cable therefrom through said idler sheave until said stop means cooperates with said carriage to limit the length of cable which is payed through said idler sheave, and to pay out additional cable therefrom to create slack in the cable between said drum and said carriage,

2. to take up cable thereon through said idler sheave to lower said carriage relative to the ground,

3. to pay out a sufficient length of cable therefrom to maintain said slack in said cable between said drum and said carriage as said first means is rotating said drive sheave to move said carriage from said drive sheavetoward said outhaul sheave, and

4. to take up cable thereon while maintaining slack in said cable between said carriage and said drum as said first means is rotating said drive sheave tomovesaid carriage from said outhaul sheave toward said drive sheave.

6. The system of claim 5 wherein said stop means is removably fixedto said cable so that said stop means can be positioned at a plurality of locations on said cable to lengthen and shorten the effective length of said cable.

7. In a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriage having one end of a cable attached thereto, said cable running through an outhaul sheave fixed in relation to the ground, through a plurality of drive sheaves through an inhaul sheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable runningfrom said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively and reversibly driven by a prime mover, the improvement comprising the steps of:

raising said balloon at a location near said inhaul sheave by stopping said drive sheaves and by paying out cable from said drum through said idler sheave, and

limiting the length of cable which can be payed out from said drum by affixing a stop member to said cable between said drum and said carriage which stop member abuts against said carriage when a predetermined amount of cable has been payed out from said drum.

8. In the method of claim 7, the improvement further comprising the step of:

lowering said balloon at a location near said inhaul sheave by stopping said drive sheaves and by taking up cable on said drum through said idler sheave.

9. In a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriage having one end of a cable attached thereto, said cable running through an outhaul sheave fixed in relation to the ground, through a plurality of drive sheaves through an inhaulsheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable running from said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively, and reversibly driven by a prime mover, the improvement in moving said balloon from a location near said inhaul sheave to a location near said outhaul sheave comprising the steps of:

affixing a stop member to said cable between said drumand said carriage and paying out a sufficient amount of cable from said drum through said idler sheave to allow said stop member to abut against said carriage thereby limiting the amount of cable payed out through said idler sheave and thereby creating slack in the cable between said drum and said stop member, and thereafter rotating said drive sheaves in a predetermined direction to drive said cable and move said balloon between said locations and simultaneously maintaining slack in said cable between said stop member and said drum by selectively rotating said drum in a predetermined direction. 10. in a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriagehaving one end of a cable attached thereto, said cable running through an outhaul sheave fixed in relation to the ground, through a plurality of drive sheaves through an inhaul sheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable running from said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively, and reversibly driven by a prime mover, the improvement comprising the steps of:

lowering said balloon at a location near said outhaul sheave by rotating said drive sheaves in a direction to take up cable through said outhaul sheave, and

simultaneously taking up cable on said drum through said idler sheave.

11. ln the method of claim 10 the improvement further comprising the steps of:

raising said balloon at a location near said outhaul sheave by rotating said drive sheaves in a direction to pay out cable through said outhaul sheave and simultaneously paying out cable from said drum through said idler sheave, and

limiting the length of cable which can be payed out from said drum through said idler sheave by affixing a stop member to said cable between said drum and said carriage which abuts against said carriage when a predetermined amount of cable has been payed out from said drum. 

1. A system for transporting objects between two locations comprising: a prime mOver; a plurality of drive sheaves and means mounting said drive sheaves for rotation; first drive means operatively associated with said prime mover for selectively and reversibly rotating said drive sheaves; a drum and means mounting said drum for rotation; second drive means operatively associated with said prime mover for selectively and reversibly rotating said drum; a carriage means having means thereon for suspending objects therefrom, said carriage means having a lighter-than-air balloon attached thereto to suspend said carriage means and said objects in the air; said carriage means having an idler sheave mounted for rotation thereon; an outhaul sheave spaced from said drive sheaves; cable means connected to said carriage means, said cable means extending from said carriage means and engaging said outhaul sheave, said cable means extending from said outhaul sheave to an engaging said drive sheaves, said cable means extending from said drive sheaves back to said carriage means and engaging said idler sheave, said cable means extending from said idler sheave to and being wrapped on said drum; and, stop means fixed to said cable means between said drum and said carriage means, said stop means for abutting said carriage means to limit the length of cable which can be payed out from said drum to and through said idler sheave on said carriage means.
 2. to take up cable thereon through said idler sheave to lower said carriage relative to the ground,
 2. The system of claim 1 wherein said stop means is removably affixed to said cable so that said stop means can be positioned at various locations along said cable to shorten and lengthen the length of cable running from said carriage means, through said outhaul sheave, said drive sheaves and said idler sheave, and back to said stop means.
 3. The system of claim 1 further comprising: first brake means operatively associated with said plurality of drive sheaves and said first drive means for preventing rotation of said drive sheaves when said second drive means is rotating said drum.
 3. to pay out a sufficient length of cable therefrom to maintain said slack in said cable between said drum and said carriage as said first means is rotating said drive sheave to move said carriage from said drive sheave toward said outhaul sheave, and
 4. The system of claim 1 further comprising: second brake means operatively associated with said drum and said second drive means for preventing rotation of said drum when said first drive means is rotating said drive sheaves.
 4. to take up cable thereon while maintaining slack in said cable between said carriage and said drum as said first means is rotating said drive sheave to move said carriage from said outhaul sheave toward said drive sheave.
 5. In a system for moving objects between two points, said system including a carriage having a means for holding objects attached thereto, said carriage having an idler sheave mounted for rotation thereon, said system further including at least one drive sheave, an outhaul sheave spaced from said drive sheave, a drum, and a cable having a first end and a second end, said drive sheave and said outhaul sheave being stationary relative to the ground, said first end of said cable being attached to said carriage and said second end of said cable being wrapped about said drum, said drum upon rotation being capable of taking up and paying out said cable, said cable from said first end running through said outhaul sheave, from said outhaul sheave through said drive sheave, from said drive sheave through said idler sheave, and from said idler sheave to said drum, the improvement comprising: a lighter-than-air balloon attached to said carriage stop means fixed to said cable between said idler sheave and said drum, said stop means for cooperating with said carriage to limit the length of said cable capable of being payed out from said drum through said idler sheave and to fix the effective length of said cable from said first end through said outhaul sheave and said drive sheave and back to said carriage, first means for reversibly rotating said drive sheave to drive said cable and thereby move said carriage between said outhaul sheave and said drive sheave, second means for selectively and reversibly rotating said drum
 6. The system of claim 5 wherein said stop means is removably fixed to said cable so that said stop means can be positioned at a plurality of locations on said cable to lengthen and shorten the effective length of said cable.
 7. In a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriage having one end of a cable attached thereto, said cable running through an outhaul sheave fixed in relation to the ground, through a plurality of drive sheaves through an inhaul sheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable running from said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively and reversibly driven by a prime mover, the improvement comprising the steps of: raising said balloon at a location near said inhaul sheave by stopping said drive sheaves and by paying out cable from said drum through said idler sheave, and limiting the length of cable which can be payed out from said drum by affixing a stop member to said cable between said drum and said carriage which stop member abuts against said carriage when a predetermined amount of cable has been payed out from said drum.
 8. In the method of claim 7, the improvement further comprising the step of: lowering said balloon at a location near said inhaul sheave by stopping said drive sheaves and by taking up cable on said drum through said idler sheave.
 9. In a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriage having one end of a cable attached thereto, said cable running through an outhaul sheave fixed in relation to the ground, through a plurality of drive sheaves through an inhaul sheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable running from said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively, and reversibly driven by a prime mover, the improvement in moving said balloon from a location near said inhaul sheave to a location near said outhaul sheave comprising the steps of: affixing a stop member to said cable between said drum and said carriage and paying out a sufficient amount of cable from said drum through said idler sheave to allow said stop member to abut against said carriage thereby limiting the amount of cable payed out through said idler sheave and thereby creating slack in the cable between said drum and said stop member, and thereafter rotating said drive sheaves in a predetermined direction to drive said cable and move said balloon between said locations and simultaneously maintaining slack in said cable between said stop member and said drum by selectively rotating said drum in a predetermined direction.
 10. In a method for transporting objects between two locations using a lighter-than-air balloon, said balloon being attached to a carriage having an idler sheave thereon, said carriage having one end of a cable attached thereto, said cable running through an outhaul sheavE fixed in relation to the ground, through a plurality of drive sheaves through an inhaul sheave fixed in relation to the ground and spaced from said outhaul sheave, and through said idler sheave, said cable running from said idler sheave to a drum onto which the other end of said cable is wound, said drive sheaves and said drum each being independently, selectively, and reversibly driven by a prime mover, the improvement comprising the steps of: lowering said balloon at a location near said outhaul sheave by rotating said drive sheaves in a direction to take up cable through said outhaul sheave, and simultaneously taking up cable on said drum through said idler sheave.
 11. In the method of claim 10 the improvement further comprising the steps of: raising said balloon at a location near said outhaul sheave by rotating said drive sheaves in a direction to pay out cable through said outhaul sheave and simultaneously paying out cable from said drum through said idler sheave, and limiting the length of cable which can be payed out from said drum through said idler sheave by affixing a stop member to said cable between said drum and said carriage which abuts against said carriage when a predetermined amount of cable has been payed out from said drum. 